Single sheet folded mailers, also known as self-mailers, are commonly used for high volume mailings of short form letters. Self-mailers produced from a single folded sheet often have one or more perforated edges to allow easy opening by the recipient. Self-mailers are typically produced from a single sheet of paper which can be printed on one or both sides and sealed around the edges. These mailers are particularly useful where large numbers of the documents are needed since they can be produced quickly from a continuous roll or supply of cut-sheet paper. Self-mailers provide an economical and efficient manner of sending bills or checks without the expense of stuffing standard envelopes. Mailers, however, are generally limited in that they are formed in a limited number of configurations and sizes which inherently reduce the area available for printing.
One form of self-mailer commonly produced in the large volume mailing industry passes a single sheet of paper through a printer where the desired information is printed on one or both sides of the paper. The address of the recipient is printed on the heading of the printing surface which will become the inside of the mailer. A transparent viewing window is often formed in the printed sheet and positioned to display the printed address when the mailer is folded and sealed. The mailer is formed by passing the printed sheet through a folding machine to overlap the window over the address and seal the mailer closed. One form of folding machine seals the side edges with an adhesive and forms perforations along opposite edges to aid in opening by the recipient. This form of self-mailer has the disadvantages of having limited space available for printing information and requiring a specific location of the information. Specifically, the location of the window limits the amount of space available for printing. In addition, the location of the address on the printed side of the sheet and the location of the window are dictated by the need to display the address of the completed mailer in a manner to ensure proper delivery by the postal service.
It is often desirable to print self-mailers on both sides of the sheet before or after folding. Most commercially available printers are able to print on only one side. Although two-sided printers are available, they are expensive, thereby increasing the capital investment. Generally, when it is necessary to print on both sides of the sheet, the sheet must be turned over and guided back to the one-sided printer where the second side is printed. This arrangement has the distinct disadvantage in cut sheet printers in that printing on both sides reduces the throughput by one half.
Continuous form printers, such as, for example, large mainframe IBM and Siemens printers, are not able to print on both sides of the sheet. With these systems, the only way to print both sides is to provide two printers connected in series so that the first side of the sheet is printed by the first printer, and the second side is printed by the second printer. This arrangement usually requires the sheet to be flipped over after leaving the first printer and before entering the second printer. This type of assembly does not slow the production rate, but doubles the cost of printing equipment.
Another form of mailer sometimes used in the industry prints a sheet on one side only with the address displayed on the upper third of the sheet. The sheet is then folded in a Z-fashion so that the address is exposed with the body of the letter sealed inside. This arrangement, while inexpensive, results in a loss of one-third of the available space for printing the desired information.
Examples of the previous systems for printing self-mailers are disclosed generally in U.S. Pat. Nos. 4,668,211 to Lubotta et al; 5,196,083 to Baker et al; 5,155,973 to Hipko et al; 5,114,128 to Harris, Jr. et al; 5,095,682 to Steidinger; 4,343,129 to Gunther, Jr. et al; and 4,912,909 to Stenner. These systems typically require complex printing devices which are expensive to purchase and operate. Accordingly, there is a continuing need in the industry for a method and apparatus for producing self-mailers which overcome the disadvantages of the previous printing and folding systems.